Search results for "PET"
showing 10 items of 12749 documents
Sr-isotope analysis of speleothems by LA-MC-ICP-MS: High temporal resolution and fast data acquisition
2017
Speleothems are well established climate archives. A wide array of geochemical proxies, including stable isotopes and trace elements are present within speleothems to reconstruct past climate variability. However, each proxy is influenced by multiple factors, often hampering robust interpretation. Sr isotope ratios (87Sr/86Sr) can provide useful information about water residence time and water mixing in the host rock, as they are not fractionated during calcite precipitation. Laser ablation multi-collector-inductively coupled plasma mass spectrometry (LA-MC-ICP-MS) has rarely been used for determination of Sr isotope signatures in speleothems, as speleothems often do not possess appropriate…
Musical Competition Culture in 19th Century Italy. The Concorso Basevi (Florence) and the Circolo Bonamici (Naples)
2021
Musical competitions played an important function in Italian musical culture of the 19th century. Florence and Naples offer two interesting examples in this field. In the Tuscan city, Abramo Basevi (1818-1885) established an annual composition competition specially dedicated to chamber music, which reached great popularity throughout Europe; the “Concorso Basevi” took place six times starting from 1861. In Naples Ferdinando Bonamici (1827-1905) showed more varied interests and organized not only composition but also performance competitions between 1863 and 1865. Both experiences, based on individual or small group initiatives, were undoubtedly fragile, but they contributed significantly to…
Influence of gamma-aminobutyric acid on baclofen intestinal absorption.
1994
Since previous studies suggested that baclofen absorption in the rat middle intestine was inhibited by beta-alanine and therefore mediated, at least in part, by the beta-aminoacid carrier, we focused our new studies on the analysis of the possible inhibition of the drug by a gamma-aminoacid model compound, gamma-aminobutyric acid (GABA). A rat jejunum in situ study was undertaken in order to evaluate the effect of GABA on baclofen absorption and to establish the inhibition model. Assays using isotonic perfusion solutions of 0.5 mM baclofen with starting GABA concentrations ranging from 0 to 100 mM are reported. The results show that the absorption rate pseudoconstants of the drug decrease a…
Partially competitive inhibition of intestinal baclofen absorption by beta-alanine, a nonessential dietary aminoacid.
1991
In situ intestinal absorption of baclofen in the rat in the presence of beta-alanine has been investigated. Through the perfusion of 0.50 mM baclofen solutions containing variable concentrations of the aminoacid (from 5 to 100 mM), a partially competitive inhibition of baclofen absorption was characterized: absorption rate pseudoconstants of the spasmolytic drug decrease as beta-alanine concentration increases, until a limiting value is obtained (36.8 per cent of that found for baclofen alone). A computer method was developed in order to calculate parameters governing baclofen absorption in the presence of beta-aminoacid, with the following results: Vm = 11.22 mM h-1; Km = 7.42 mM; Ki = 2.4…
Intestinal absorption pathway of gamma-aminobutyric acid in rat small intestine.
1994
Intestinal absorption of gamma-aminobutyric acid (GABA), as a model compound for gamma-aminoacids, has not been extensively studied from the kinetic viewpoint. Since data from our laboratory suggested that some competition arises between intestinal absorption of beta-alanine and GABA and since our intent was to maintain the aqueous stagnant diffusion layer in order to approach absorption tests to in vivo physiological conditions, a rat jejunum in situ study was undertaken in order to gain an insight into the mechanism of GABA absorption. In the present paper, results from assays using isotonic perfusion solutions with starting GABA concentrations ranging from 1 to 50 mM are reported. They s…
Evidence of competitive inhibition for the intestinal absorption of baclofen by phenylalanine
1996
Abstract Previous studies showed that the absorption of the antispastic drug baclofen, in the rat middle intestine, is inhibited by β-alanine, γ-aminobutyric acid (GABA) and leucine. It was concluded that baclofen intestinal transport was mediated, at least in part, by the β-, γ- and α-amino acid carriers. We therefore focused our next studies on the analysis of the possible inhibition of drug absorption by an aromatic α-amino acid model compound, phenylalanine. An in situ study in the rat small intestine was undertaken in order to evaluate the effect of phenylalanine on baclofen absorption and to establish the inhibition model. Assays using isotonic perfusion solutions of 0.5 mM baclofen w…
Absorptive Capacity and Social Capital: Innovation and Environmental Regulation
2010
Norwegian paper and pulp mills are subject to strict environmental regulation. The mills conduct research and development for reducing pollution. Absorptive capacity indicates their competence. Firms are part of a social network of connections with external actors that include other paper and pulp mills, suppliers, customers, research institutes, and universities that help them in developing technologies. These relations represent their social capital. Some firms have access to more and better resources than other firms. Measuring firms’ absorptive capacity and access to social capital, we analyze their success in reducing pollution levels. There is a strong interaction effect between absor…
María Magdalena. Continuidad y variación en la cultura audiovisual (1897-2014)
2017
El objetivo principal de esta tesis consiste en analizar la presencia de María Magdalena en las producciones audiovisuales del periodo comprendido entre 1897 y 2014. Dichas producciones proceden de Europa, Estados Unidos, Canadá y México. El marco metodológico general a partir del que se plantea el análisis es la iconología, entendida como Zwichenraum o tierra de confluencias. En concreto, la noción de continuidad y variación, iniciada por Aby Warburg y continuada por Fritz Saxl, es la principal cuestión teórica en la que se basa la aproximación. El estudio se lleva a cabo en perspectiva diacrónica con el objetivo de detectar dichas fases de continuidad y variación del personaje a lo largo …
Training Programs – Training and Development Alternatives for Students
2013
Abstract Training programs have been established as a form of training for adults, being generally used within companies’ personal development alternatives starting from the employees’ performance assessment processes. The current century requires a different way of approaching academic education, starting from the employers’ observation in reference to the lack of the graduates’ key competencies in the hiring process. We intend to demonstrate that it is useful to introduce training programs as an alternative form of education in academia, as well as in the high school environment.
The Necessary Competences for Student Success in the First Academic Year
2013
En ligne sur : http://infonomics-society.org/IJCDSE/The%20Necessary%20Competences%20for%20Student%20Success%20in%20the%20First%20Academic%20Year.pdf; International audience; This paper tries to show which competences have an impact on the success of students in higher education and especially in the first academic year. This situation also requires finding a way to acquire the competences which are necessary in this new experience that is the first year. A student is considered to be a person who has the basic competences required. Our role is to show how this person in higher education can acquire the other new competences that help him/her attain the positive results that we name ''succes…